This invention relates to a manner of delivering substances into a mammalian body, and more particulary concerns delivery of polypeptide into a mammalian body.
Ionic substances have previously been delivered into body tissue by iontophoretic means. This method for delivering substances such as chemicals or drugs normally utilizes direct electrical current in contact with the skin, and drives these substances through intact skin to the interior of the animal body, including the blood stream. Iontophoresis has been shown to be useful in various medical applications and substances such a lidocaine, hydrocortisone and many other drugs have been so administered.
Various iontophoretic devices and systems have been previously described and comprise a source for generating current, a pair of electrodes and the ionic substance to be introduced into the body. The active electrode, the donor electrode that drives the desired substance through the skin, is of the same charge as the substance.
It is preferable that the active electrode also physically embrace a source for the drugs, and this can be accomplished by retaining the drug in a compatible matrix, such as a polymeric matrix, e.g. a gel or a solution contained by a semipermable membrane, or even a moist cloth or gauze and water system which will permit flow of electrically charged substance to and through the skin. Transdermal patches which contain the drug, a matrix and water are the preferred mode for transdermally administering the active agent to the human or non-human animal patient.
European Patent Application 0278 473 discloses a chemical composition and system for iontophoretic transport which comprises a protein, a cosolvent with negative Setschenow constant and water. The protein which may be used includes, but is not limited to, polypeptides having more than about 20 peptide units. The various proteins mentioned include but are not limited to calcitonin and insulin.
Iontophoretic transdermal delivery of insulin, which is a 51 peptide protein is disclosed by Chien, et al, J. Pharmaceutical Sciences 78, 5, 376-383 May 1989.
It is an object of the present invention to provide a means for iontophoretically delivering transdermally calcitonin, especially salmon calcitonin, into animal tissue.
It is a further object to provide a method for delivering calcitonin by iontophoretic transdermal means to a human or a non-human patient without the use of a cosolvent in the drug reservoir.
A further object is the provision of a transdermal device for delivering calcitonin by iontophoresis into animal tissue.